Susanna Voltolini

Bet v 1‐like pollen allergens of multiple Fagales species can sensitize atopic individuals

In the temperate climate zone of the Northern hemisphere, Fagales pollen allergy represents the main cause of winter/spring pollinosis. Among Fagales trees, pollen allergies are strongly associated within the Betulaceae and the Fagaceae families. It is widely accepted that Fagales pollen allergies are initiated by sensitization against Bet v 1, the birch pollen major allergen, although evidence is accumulating that the allergenic activity of some Bet v 1‐like molecules has been underestimated.

Effect of seasonal exposure to pollen on specific bronchial sensitivity in allergic patients

Bronchial provocation tests with aerosol of birch extract were performed before and after pollen season in 11 sensitized subjects. Changes of metacholine bronchial responsiveness and serum-specific IgE level were also assessed. In five patients who did not take steroids to control their symptoms, both early and late asthmatic responses to inhaled allergen were enhanced after season, whereas IgE serum level, but not methacholine sensitivity, was significantly increased. In six patients who needed steroids, neither responses to allergen nor IgE serum level and methacholine sensitivity were significantly changed after season. For the whole group, the increase in immediate bronchial sensitivity to allergen was positively correlated with the increase in specific IgE antibodies. We conclude that seasonal exposure to pollen has, in sensitized patients, a priming effect on bronchial mucosa that may be blunted by steroid treatment. The increased production of specific IgE antibodies appears to be an important mechanism for this priming effect.

Local immunotherapy with Dermatophagoides extract in asthma

Local immunotherapy (LIT) with Dermatophagoides extract or placebo were administered to two groups of 11 patients with allergic asthma in a double-blind fashion. All patients received cromolyn sodium (20 mg four times a day) during treatments. Bronchial provocation tests with allergen and methacholine were performed before, 1 week, and 4 weeks after the end of treatments. Symptom score, drug consumption, and peak expiratory flow were monitored daily from 2 weeks before to 4 weeks after treatments. Compared to baseline, early bronchial sensitivity to allergen was significantly reduced both 1 week (p less than 0.0005) and 4 weeks (p less than 0.01) after LIT but not after placebo administration. Late bronchial reaction to allergen occurred similarly after placebo administration and LIT. However, in the group with LIT, the severity of late reaction was unchanged after treatment in spite of the significantly larger doses of allergen administered to provoke the early asthmatic reaction. Neither symptom score, nor drug consumption, nor peak expiratory flow were significantly different in the two groups before and during the treatment period even though both symptom score and drug consumption tended to be reduced after LIT. We conclude that LIT may be an effective and safe alternative to traditional immunotherapy.

Comparison between Urticaceae (Parietaria) pollen count and hay fever symptoms: assessment of a «threshold-value»

SummaryA comparison betweenParietaria pollen count and allergic symptoms of rhino-conjunctivitis in the early season was used in utilized to determine a «threshold-value» for this pollen. Clinical data were obtained from diary-cards of 34 allergic patients and pollen data from a volumetric sampling, carried out by means of a Hirst-Burkard pollen-trap. A significant correlation (r=0.98) was found between pollen count and symptom scores. Mild symptoms were registered with concentrations above 10–15 pollens/m3. Severe symptoms occurred when pollen count exceeded 80/m3/24 h., and over 90% of patients recorded symptoms. The importance of the late reactions and of the total allergenic airborne content are emphasized.

Airborne pollen in Genoa (NW-Italy): a comparison between two pollen-sampling stations

A comparison between two pollen-sampling stationsin the city area of Genoa is presented. The samplingsites are placed 3 km apart, respectively in theeastern urban area (St. Martino Hospital – S.M.) andin the historical centre (Botanical Garden – B.G.).Pollen sampling was carried out during the years1995–1997 at the two different sites by volumetricHirst-type sampler and then compared. The dailyairborne pollen concentration of Urticaceae, Poaceae,Cupressaceae/Taxaceae, Corylaceae/Betulaceae andOleaceae resulted prevailingly higher at S.M., while a good correspondence was observed from a phenologicpoint of view. Asteraceae have shown the bestqualitative-quantitative consistency. In springtime adifference was recorded for Urticales, maybe due tolocal occurence (B.G.) of Broussonetia papyrifera(Moraceae). On the whole, the correspondence betweenthe two different sampling stations proved to besatisfactory.

Effectiveness of high dose sublingual immunotherapy to induce a stepdown of seasonal asthma: a pilot study

Abstract Background: There is ample evidence to support the efficacy of sublingual immunotherapy (SLIT) on allergic rhinitis, while there is less solid data regarding asthma. We evaluated the effects of a high dose birch SLIT on birch-induced rhinitis and asthma in a controlled study. Methods: This double-blind, placebo-controlled, randomised, single centre trial on SLIT with birch pollen allergen extract (Stallergenes, Antony, France) included 24 patients presenting severe rhinitis and slight to moderate asthma, 14 actively and 10 placebo treated. SLIT was performed by a pre-coseasonal protocol, and was repeated for 2 years. The study plan included a selection visit, a visit at the start of the first and the second treatment cycle, a follow-up visit after 1–3 months from the start of each cycle, and a final visit at the end of each yearly cycle. Results: A significant decrease (p < 0.05) in rhinorrhoea and nasal obstruction occurred in actively treated patients. The median number of days with asthma at visit 3 was 10 (0–27) in the active (SLIT) group and 13 (0–29) in the placebo group. The median number of days with asthma at visit 6 was 2 (0–6) in the SLIT group and 7 (0–15) in the placebo group (p < 0.05 between groups). A stepdown of asthma occurred in 77% of actively treated vs. none of placebo treated patients (p = 0.05). No severe adverse events were observed. Conclusions: This pilot study suggests that SLIT with high dose birch extract may be able to step down seasonal pollen-induced asthma after prolonged treatment.

Late asthmatic reaction to perennial and seasonal allergens

Twelve patients with asthma sensitized to Dermatophagoides pteronyssinus and Parietaria judaica were studied. Patients were challenged before (winter), during (summer), and after (autumn) Parietaria-pollen season. Early asthmatic reaction was positive for both allergens, and the provocative dose causing a 15% decrease of FEV1 was similar in all seasons. The provocative dose of methacholine causing a 15% decrease of FEV1 and specific IgEs for both allergens were also not significantly different throughout the time of study. Late asthmatic reaction (LAR) to Dermatophagoides occurred in eight of 12 patients in winter, in six of nine in summer, and in five of six patients in autumn. The severity of LAR, expressed as the maximum fall of FEV1 3 to 8 hours after challenge, was not significantly different between seasons. LAR to Parietaria occurred in only one of 12 patients in winter, in six of 11 in summer, and in one of six patients in autumn. In summer, LAR to Parietaria was significantly more severe than in winter. In both winter and autumn, but not in summer, LAR to Dermatophagoides was significantly more severe than to Parietaria. We conclude that LAR is allergen specific, and natural exposure has a priming effect on LAR.

Food allergy to Boletus edulis

Boletus edulis (boler) is a highly appreciated edible mushroom that is widely used in Italian cuisine. Adverse reactions after its ingestion were believed to be due to a deficiency of trehalase, t an enzyme required in the metabolism of trehalose, a glycidic component commonly present in mushrooms. Recently, a case of occupational allergy to baler was reported without any consideration about the possible allergens involved. We describe a clinical case of food allergy to boler, including characterization of the patients serum IgE reactivity.

Birch allergy and oral allergy syndrome: The practical relevance of serum immunoglobulin E to Bet v 1.

BACKGROUND Birch allergy (BA) may frequently be associated with fruit-vegetables oral allergy syndrome (OAS). Bet v 1 is the major birch allergen. Previously, it was reported that serum-specific immunoglobulin E (IgE) level could differentiate allergy from sensitization. Thus, this study aimed to investigate the practical role of Bet v 1 IgE. METHODS A total of 245 subjects (128 women, 117 men; mean age, 41 years) with suspected allergic rhinitis and sensitization to Bet v 1 were evaluated. Serum IgE to Bet v 1 was assessed by using immuno-enzymatic. BA and OAS were diagnosed according to validated criteria. Symptom severity perception was measured by the visual analog scale. RESULTS A total of 158 patients (64.5%) had BA. Patients with BA had higher serum Bet v 1 IgE levels than subjects who were sensitized (p < 0.0001). A cutoff value of 8.94 kUA/L predicted BA (area under the curve, 0.76; odds ratio, 6.18). Fifty-three patients with BA (33.5%) had OAS. Patients positive for OAS had higher Bet v 1 levels (p < 0.0001) and more-severe symptoms (p < 0.0001) than patients with BA and negative for OAS. A cutoff value of 17.4 kUA/L predicted OAS (area under the curve, 0.59; odds ratio, 3.19). CONCLUSIONS The present study demonstrated that serum IgE levels to Bet v 1 could be a useful marker for differentiating between different birch pollen sensitization phenotypes.

Value of immunoglobulin E density in predicting nasal and bronchial response to inhaled allergens in rhinitic and asthmatic subjects with multiple sensitizations.

In atopic subjects with multiple sensitizations to inhalant allergens the relationship between the specific serum immunoglobulin (Ig) E and the in vivo response to each allergen is not well established.